94 research outputs found

    Site investigations and convergence measurements for a twin metro tunnel driven in Ankara clay, Turkey

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    © The Geological Society of London 2006 10th Congress of the International Association for Engineering Geology and the Environment – Engineering geology for tomorrow’s citiesOver population and increase in the traffic congestion in urban areas have led to an inevitable rise in the construction of underground structures. Therefore, a project consisting of 9325m twin metro tunnel construction has been planned by the Greater Municipality of Ankara in order to help to ease transportation problems in Ankara, Turkey. This paper presents the geotechnical properties along the tunnel route, and construction of the Middle East Technical University (METU) twin metro tunnel between 2.720 and 4.000 km as a part of Ankara project III. The twin metro tunnel runs mainly through Ankara Clay above this is artificial fill material. Each tunnel has approximately 38 m2 cross-sectional area and is excavated in two stages in accordance with New Austrian Tunnelling Method (NATM). There have been several drilling holes conducted to investigate groundwater levels and engineering properties of the host medium; these will be examined in the paper. In order to monitor the amount of tunnel closure, convergence measurements taken during construction of the tunnel will be presented and discussed.Aydin Ozsan and Murat Karaku

    Support capacity estimation of a diversion tunnel in weak rock

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    This paper presents the results of the support capacity estimation for the diversion tunnel of the Urus dam site in highly weathered tuff and weak zone. Tunneling in weak rock requires some special considerations, since misjudgment in support design results in costly failures. There are several ways of estimating rock support pressure and selecting support. However, all systems suffer from their characteristic limitations in achieving objectives. Thus, it is more useful to use different methods for estimating support pressure and type of support. The support pressure pi was established by three different methods. These methods are the (1) empirical methods based on rock mass rating (RMR) and rock mass quality index (Q-classification systems), (2) ground support interaction analysis (GSIA) and (3) numerical methods, namely, Phase 2 finite element (FEM) program. Rock masses were characterized in terms of RSR, RMR, Q-system and GSI. Drill-core samples were tested in the rock mechanics laboratory to determine physico-mechanical properties. Rock mass strength was estimated by empirical methods. Finally, the required support system is proposed and evaluated by different methods in the highly weathered tuff and weak zone of the diversion tunnel

    Geotechnical rock-mass evaluation of the Anamur dam site, Turkey

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    This paper describes a feasibility-level geotechnical evaluation carried out at Anamur dam site, in terms of stability analysis of dam foundation, excavation slopes and a diversion tunnel. The proposed Anamur dam will be built across the Anamur river on the Alanya metamorphic series which consists of phyllite, schist and slate units at the site. Geotechnical investigations included drilling for core, pumping tests, sampling for laboratory testing, and a detailed discontinuity survey

    Preliminary support design for Ankara subway extension tunnel

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    This paper presents the results of preliminary support design of the subway tunnel for Ankara subway project in accordance with some empirical and numerical methods, using the phase 2D finite element method (FEM). The 5 m diameter subway tunnel will advance through slightly to moderately weathered dacite and weak zones. Rock masses were characterized in terms of rock mass rating (RMR), geological strength index (GSI) and Q System. Core samples were tested in the rock mechanics laboratory to determine uniaxial compressive strength, deformability parameters, unit weight, tensile strength and triaxial compressive strength properties. Finally, rock mass strengths were determined by empirical and numerical methods. Required support system was suggested

    Finite element analysis for the twin metro tunnel constructed in Ankara Clay, Turkey

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    The paper presents the geotechnical properties along the route of the 9,325 m twin tunnel metro route in the Greater Municipality of Ankara. Convergence measurements taken during tunnel construction are presented and discussed. In addition, the convergence of the twin metro tunnels was analysed by means of a 2D plane strain finite element (FE) analysis. The FE model estimations and the field measurements are compared. © Springer-Verlag 2006.Murat Karakus, Aydın Ozsan and Hakan Başarı

    Analysis of support requirements for a shallow diversion tunnel at Guledar dam site, Turkey

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    Engineering geological properties and support design of a planned diversion tunnel at Guledar dam site, which was located at the North of Ankara, Turkey were studied in this article. The main purpose of the construction of the planned tunnel is to regulate, drainage and to provide water for irrigation purposes. The diversion tunnel runs mainly through formations of limestone, sandstone and diabase. Rock masses at the site were characterized using Rock Mass Rating (RMR), Rock Mass Quality (Q), Rock Mass Index (RMi) and Geological Strength Index (GSI). RMR, Q, RMi and GSI were determined by using field data and mechanical properties of intact rock samples, measured in the laboratory. Support requirements for the planned diversion tunnel were determined accordingly in terms of the rock mass classification systems. Recommended support systems by empirical methods were also analyzed using 2D Finite Element method. Calculated parameters based on empirical methods were used as input parameters in the finite element models. The results from both methods were compared with each other. This comparison suggests that more reliable support design could be achieved by using the finite element method together with the empirical methods.H. Basarira, A. Ozsanb and M. Karakushttp://www.elsevier.com/wps/find/journaldescription.cws_home/503330/description#descriptio

    GENETIC AND NON-GENETIC TYPE OF STEROID-RESISTANT NEPHROTIC SYNDROME AND CYCLOSPORINE A RESPONSE

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    WOS: 00026858450009
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